(function(window) {
	//兼容
	window.URL = window.URL || window.webkitURL;
	navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia ||
		navigator.msGetUserMedia;
	var HZRecorder = function(stream, config) {
		config = config || {};
		config.sampleBits = config.sampleBits || 8; //采样数位 8, 16,128
		config.sampleRate = config.sampleRate || (44100 / 6); //采样率(1/6 44100)

		var context = new(window.webkitAudioContext || window.AudioContext)();
		var audioInput = context.createMediaStreamSource(stream);
		var createScript = context.createScriptProcessor || context.createJavaScriptNode;
		var recorder = createScript.apply(context, [4096, 1, 1]);//bufferSize大小，输入channel数，输出channel数


		var audioData = {
			size: 0, //录音文件长度
				
			buffer: [], //录音缓存
				
			inputSampleRate: context.sampleRate, //输入采样率
				
			inputSampleBits: 16 ,//输入采样数位 8, 16
				
			outputSampleRate: config.sampleRate	, //输出采样率
			
			oututSampleBits: config.sampleBits ,//输出采样数位 8, 16
				
			input: function(data) {
				this.buffer.push(new Float32Array(data));
				this.size += data.length;
			},
			compress: function() { //合并压缩
				//合并
				var data = new Float32Array(this.size);
				var offset = 0;
				for (var i = 0; i < this.buffer.length; i++) {
					data.set(this.buffer[i], offset);
					offset += this.buffer[i].length;
				}
				//压缩
				var compression = parseInt(this.inputSampleRate / this.outputSampleRate);
				var length = data.length / compression;
				var result = new Float32Array(length);
				var index = 0,
					j = 0;
				while (index < length) {
					result[index] = data[j];
					j += compression;
					index++;
				}
				return result;
			},
			encodeWAV: function() {
				var sampleRate = Math.min(this.inputSampleRate, this.outputSampleRate);
				var sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits);
				var bytes = this.compress();
				var dataLength = bytes.length * (sampleBits / 8);
				var buffer = new ArrayBuffer(44 + dataLength);
				var data = new DataView(buffer);

				var channelCount = 1; //单声道
				var offset = 0;

				var writeString = function(str) {
					for (var i = 0; i < str.length; i++) {
						data.setUint8(offset + i, str.charCodeAt(i));
					}
				}

				// 资源交换文件标识符
				writeString('RIFF');
				offset += 4;
				// 下个地址开始到文件尾总字节数,即文件大小-8
				data.setUint32(offset, 36 + dataLength, true);
				offset += 4;
				// WAV文件标志
				writeString('WAVE');
				offset += 4;
				// 波形格式标志
				writeString('fmt ');
				offset += 4;
				// 过滤字节,一般为 0x10 = 16
				data.setUint32(offset, 16, true);
				offset += 4;
				// 格式类别 (PCM形式采样数据)
				data.setUint16(offset, 1, true);
				offset += 2;
				// 通道数
				data.setUint16(offset, channelCount, true);
				offset += 2;
				// 采样率,每秒样本数,表示每个通道的播放速度
				data.setUint32(offset, sampleRate, true);
				offset += 4;
				// 波形数据传输率 (每秒平均字节数) 单声道×每秒数据位数×每样本数据位/8
				data.setUint32(offset, channelCount * sampleRate * (sampleBits / 8), true);
				offset += 4;
				// 快数据调整数 采样一次占用字节数 单声道×每样本的数据位数/8
				data.setUint16(offset, channelCount * (sampleBits / 8), true);
				offset += 2;
				// 每样本数据位数
				data.setUint16(offset, sampleBits, true);
				offset += 2;
				// 数据标识符
				writeString('data');
				offset += 4;
				// 采样数据总数,即数据总大小-44
				data.setUint32(offset, dataLength, true);
				offset += 4;
				// 写入采样数据
				if (sampleBits === 8) {
					for (var i = 0; i < bytes.length; i++, offset++) {
						var s = Math.max(-1, Math.min(1, bytes[i]));
						var val = s < 0 ? s * 0x8000 : s * 0x7FFF;
						val = parseInt(255 / (65535 / (val + 32768)));
						data.setInt8(offset, val, true);
					}
				} else {
					for (var i = 0; i < bytes.length; i++, offset += 2) {
						var s = Math.max(-1, Math.min(1, bytes[i]));
						data.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true);
					}
				}

				return new Blob([data], {
					type: 'audio/mp3'
				});
			}
		};

		//开始录音
		this.start = function() {
			audioInput.connect(recorder);
			recorder.connect(context.destination);
		}

		//停止
		this.stop = function() {

			recorder.disconnect();
		}

		//获取音频文件
		this.getBlob = function() {
			this.stop();
			return audioData.encodeWAV();
		}

		//回放
		this.play = function(audio) {
			var downRec = document.getElementById("downloadRec");
			downRec.href = window.URL.createObjectURL(this.getBlob());
			downRec.download = new Date().toLocaleString() + ".mp3";
			audio.src = window.URL.createObjectURL(this.getBlob());
		}

		//上传
		this.upload = function(url, callback) {
			var fd = new FormData();
			fd.append("audioData", this.getBlob());
			var xhr = new XMLHttpRequest();
			if (callback) {
				xhr.upload.addEventListener("progress", function(e) {
					callback('uploading', e);
				}, false);
				xhr.addEventListener("load", function(e) {
					callback('ok', e);
				}, false);
				xhr.addEventListener("error", function(e) {
					callback('error', e);
				}, false);
				xhr.addEventListener("abort", function(e) {
					callback('cancel', e);
				}, false);
			}
			xhr.open("POST", url);
			xhr.send(fd);
		}

		//音频采集
		recorder.onaudioprocess = function(e) {
			audioData.input(e.inputBuffer.getChannelData(0));
			//record(e.inputBuffer.getChannelData(0));
		}

	};
	//抛出异常
	HZRecorder.throwError = function(message) {
		alert(message);
		throw new function() {
			this.toString = function() {
				return message;
			}
		}
	}
	//是否支持录音
	HZRecorder.canRecording = (navigator.getUserMedia != null);
	//获取录音机
	HZRecorder.get = function(callback, config) {
		if (callback) {
			if (navigator.getUserMedia) {
				navigator.getUserMedia({
						audio: true
					} //只启用音频
					,
					function(stream) {
						var rec = new HZRecorder(stream, config);
						callback(rec);
					},
					function(error) {
						switch (error.code || error.name) {
							case 'PERMISSION_DENIED':
							case 'PermissionDeniedError':
								HZRecorder.throwError('用户拒绝提供信息。');
								break;
							case 'NOT_SUPPORTED_ERROR':
							case 'NotSupportedError':
								HZRecorder.throwError('浏览器不支持硬件设备。');
								break;
							case 'MANDATORY_UNSATISFIED_ERROR':
							case 'MandatoryUnsatisfiedError':
								HZRecorder.throwError('无法发现指定的硬件设备。');
								break;
							default:
								HZRecorder.throwError('无法打开麦克风。异常信息:' + (error.code || error.name));
								break;
						}
					});
			} else {
				HZRecorder.throwErr('当前浏览器不支持录音功能。');
				return;
			}
		}
	}

	window.HZRecorder = HZRecorder;

})(window);

